CN214407524U

CN214407524U - Fiber grating sensor

Info

Publication number: CN214407524U
Application number: CN202120298157.2U
Authority: CN
Inventors: 陈少洋
Original assignee: Beijing Dacheng Yongsheng Technology Co ltd
Current assignee: Beijing Dacheng Yongsheng Technology Co ltd
Priority date: 2021-02-03
Filing date: 2021-02-03
Publication date: 2021-10-15
Anticipated expiration: 2031-02-03

Abstract

The utility model provides a fiber grating sensor, which comprises an optical fiber joint, and an optical fiber with a fiber grating, which is extended out from the optical fiber joint; the other end of the optical fiber is a closed end or extends into another optical fiber joint; the seamless tube is sleeved on the outer side of the optical fiber, and the insulating tube is further coated on the outer side of the seamless tube. The fiber grating sensor main body part is packaged by adopting the insulating tube and the seamless tube, so that the fiber grating sensor has the characteristics of high tensile strength, high compression resistance and overall high strength under the protection of the seamless tube, and has the characteristics of insulation, acid resistance, alkali resistance, salt corrosion and the like under the protection of the insulating tube.

Description

Fiber grating sensor

Technical Field

The utility model relates to an optical fiber sensor technical field, more specifically say, relate to a fiber grating sensor.

Background

The fiber grating is positioned in the optical fiber, and is often used for sensing by utilizing the characteristic that the refractive index of the optical fiber can be periodically changed; since the fiber grating itself is a part of the optical fiber, it is referred to as "an optical fiber with a fiber grating" in the specification of the present invention. The fiber grating can be used for measuring basic physical quantities in the nature, such as external information of temperature, strain, stress and the like, by matching with corresponding measuring equipment. The optical fiber with the fiber grating is naturally fragile, so that the optical fiber is not suitable for most practical engineering applications and can only be applied to the laboratory research stage. After the above work is completed, the product can be called as a fiber grating sensor, and can also be called as a fiber grating temperature sensor, a fiber grating strain sensor, a fiber grating stress sensor and the like according to the tested physical quantity.

Due to the characteristics of the optical fiber material, the vulnerability of the test main body in the optical fiber grating sensor is a problem which puzzles the industry for many years, and particularly, the application of the optical fiber grating in some special environments and even extreme environments is limited, such as environments with corrosivity, such as high tensile force, high pressure, electrification, acid, alkali, salt and the like, so that the optical fiber grating sensor is greatly restricted in the practical industrial application.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a fiber grating sensor to the test main part that solves in the fiber grating sensor is fragile, ordinary encapsulation is uninsulated, does not endure the little problem of range of application of corruption such as acid-base salt, sensor.

The utility model aims at realizing through the following technical scheme:

the utility model provides a fiber grating sensor, which comprises an optical fiber joint, and an optical fiber with a fiber grating, which is extended out from the optical fiber joint; the other end of the optical fiber is a closed end or extends into another optical fiber joint; the seamless tube is sleeved on the outer side of the optical fiber, and the insulating tube is further coated on the outer side of the seamless tube.

The fiber grating sensor has the advantages that the seamless metal pipe/seamless alloy pipe is adopted to package the main body part of the fiber grating sensor, and the metal pipe or the alloy pipe is simultaneously nested with the insulating materials such as the rubber pipe/the plastic pipe/the resin pipe, so that the fiber grating sensor has the characteristics of high tensile strength, high compression resistance and overall high strength under the protection of the metal pipe or the alloy pipe, and has the characteristics of insulation, acid resistance, alkali resistance, salt corrosion and the like under the protection of the rubber pipe/the plastic pipe/the resin pipe. Therefore, the technical scheme of the application not only solves the problems of fragility of the optical fiber with the fiber grating and uninsulation of the metal tube or the alloy tube, but also solves the problems of acid, alkali, salt and other corrosion resistance of the common package at low cost, and expands the application range of the fiber grating sensor.

One, fiber grating sensor is become by following four bibliographic categories:

1. and (3) optical fiber joint: the optical fiber connector of the fiber grating sensor is a part of the sensor, the type of the optical fiber connector is a common connector in the market, and the optical fiber connector shown in the attached drawing is only schematic. The fiber joint is used for connecting the fiber grating sensor to an optical transmission network or various fiber grating sensing devices (the fiber grating sensor has only detection and transmission functions and cannot directly display information such as temperature, strain, stress and the like, and the information is given by the fiber grating sensing devices).

2. The fiber grating sensor main body is internally provided with fiber gratings: the main sensing part of the fiber grating sensor is also the main object of subsequent packaging, the fiber grating on the fiber is a single-point fiber grating or a multi-point fiber grating, and because there are many kinds of fibers that can be used for writing the fiber grating and also many kinds of fiber gratings, the fiber/fiber grating is not limited here, and the number of the fiber gratings included in the fiber is not limited.

3. Packaging the fiber grating sensor main body: the packaging structure of the fiber grating sensor main body is divided into two layers, wherein the inner layer is a seamless metal tube or a seamless alloy tube, wherein a seamless stainless steel tube is commonly used, and can be various alloy tubes according to different use environments, even can be different metal tubes such as an aluminum tube, a copper tube and the like. The outer layer insulating pipe is mainly a plastic pipe/rubber pipe/resin pipe. The outer diameter of the main body part of the sensor after encapsulation is generally 0.6mm, 0.9mm, 2.0mm and 3.0mm (these four dimensions are typical dimensions), and currently, the outer diameter of the insulating tube is generally not more than 3.2mm and not less than 0.2 mm. The length of the fiber grating sensor is currently not limited, and the total length can range from several centimeters to tens of kilometers.

4. Packaging the closed end of the fiber grating sensor: for the structure of the single-ended fiber grating sensor, the closed end of the fiber grating sensor needs to be sealed. Our seals have three main forms, one is a welded seal, one is an end cap mount seal, and the other is a glue seal; the above three sealing forms can be used alone or in combination for the combination of seamless pipes and insulating pipes of different materials.

On the closed end side of the fiber grating sensor, the fiber with the fiber grating is not longer than the seamless tube, and the seamless tube is not longer than the insulating tube.

For the structure of the double-end fiber grating sensor, the two ends of the fiber grating sensor are both fiber connectors, the types of the fiber connectors can be the same or different, and the fiber grating sensors at the two ends can be used in series.

Of course, there are many preferred embodiments or implementations of the present application in a particular implementation:

5. preferably, the seamless pipe is a seamless metal pipe or a seamless alloy pipe.

Preferably, the seamless pipe is a seamless stainless steel pipe, a seamless copper pipe or a seamless aluminum pipe.

Preferably, the insulating tube is a rubber tube.

Preferably, the insulating tube is a plastic tube.

Preferably, the insulating tube is a resin tube.

Preferably, the closed end is sealed by a weld seal, an end cap seal or glue.

Preferably, a lapping metal tube or a stranded steel wire layer is further nested between the seamless tube and the insulating tube.

Preferably, the outer diameter of the insulating tube after the seamless tube is coated is 0.2-3.2 mm.

Two, inner integral connection

The sensing and communication functions of the fiber grating sensor are performed by the internal fiber and the fiber grating, so the fiber usually containing the fiber grating extends from the fiber connector head to the closed end or another fiber connector, and a cavity can be left in the case that one end is closed.

At the joint part of the fiber grating sensor, the optical fiber is inserted into the optical fiber joint, the joint is formed by grinding, clamping or crimping special equipment, and the optical fiber can be directly connected to an optical transmission network or equipment matched with various joints. In the main body of the fiber grating sensor, the optical fiber with the fiber grating is directly placed, and various buffer materials, such as glass fiber, Kevlar fiber and the like (optional), can be wrapped on the optical fiber with the fiber grating, the main body can be internally provided with air, can be filled with nitrogen or inert gas to protect the optical fiber (optional), and can also be liquid such as heat conduction oil and the like (optional). Present better high strength fiber grating sensor's encapsulation probably is the tubular metal resonator encapsulation (the sensor intensity of traditional nonmetal pipe encapsulation is very poor), but the metal is electrically conductive, can't use in some electrified environment, the utility model discloses it does further sealed protection to have increased insulating material such as rubber tube/plastic tubing/resin pipe outside the tubular metal resonator, has realized the insulating characteristic of certain degree.

Present better fibre-optical grating sensor's of acidproof, alkali, salt etc. corruption encapsulation maybe the tubular metal resonator encapsulation, but can resist the metal cost of corruption such as acid, alkali, salt expensive, the utility model discloses it is further sealed protection to have increased materials such as rubber tube/plastic tubing/resin pipe outside the tubular metal resonator, has realized the encapsulation characteristic of corrosion such as acidproof, alkali, salt of fibre-optical grating sensor with lower cost.

Because the utility model discloses a seamless metal pipe/seamless alloy pipe and rubber tube/plastic tubing/resin pipe carry out nested encapsulation to fiber grating sensor main part, can accomplish that application scope is extremely wide (can bury, can twine, can cloth in environment such as oil, water, corrosive gas liquid, radiation, electrified), have enlarged the trade range of application of fiber grating sensing.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a single-ended fiber grating sensor according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a double-ended fiber grating sensor according to an embodiment of the present invention;

wherein: 1-optical fiber with fiber grating, 2-seamless tube, 3-optical fiber joint, 4-sealed end, 5-insulating tube.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. It is obvious that the described embodiments are only some of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

An object of the present embodiment is to provide a fiber grating sensor, which solves the problems that a test subject in the fiber grating sensor is fragile, a common package is not suitable for a charged environment, a corrosive environment, and the application range of the fiber grating sensor is small.

Hereinafter, embodiments will be described with reference to the drawings. The embodiments described below do not limit the scope of the invention described in the claims.

Referring to fig. 1 to 2, the present embodiment provides a fiber grating sensor, including an optical fiber 1 with a fiber grating, in the technical solution of the present application, the optical fiber 1 mainly refers to a section of the optical fiber with the fiber grating between an optical fiber connector 3 and a sealed end 4 (as shown in fig. 1) or between the optical fiber connector and the optical fiber connector (as shown in fig. 2), where the optical fiber 1 may be one or multiple optical fibers; the fiber grating on the optical fiber 1 may be a single point or a plurality of points. The fiber grating sensor also comprises a seamless tube 2 sleeved outside the optical fiber 1 with the fiber grating. Referring to fig. 2, both ends of the seamless tube 2 are connected with optical fiber connectors 3, or referring to fig. 1, one end of the seamless tube 2 is connected with the optical fiber connectors 3, the other end is a sealed end 4, and the optical fiber 1 with the fiber grating extends from the optical fiber connectors 3 to the sealed end 4, and in some applications, a cavity can be left. The optical fiber connector 3 is used for connecting an optical transmission network or various optical fiber grating sensing devices, the optical fiber grating sensor has only detection and transmission functions and cannot directly display information such as temperature, strain, stress and the like, and the information is given by the optical fiber grating sensing devices. The fiber grating sensor packaged by the insulating tube 5 has the characteristics of high tensile strength, high compression resistance, wear resistance, insulation and corrosion resistance, so that the fiber grating sensor has a wide application range, can be buried and wound, can be distributed in oil, water, corrosive gas and liquid, radiation, electrification and other environments, and the industrial application of the fiber grating sensing industry is expanded.

In one embodiment of the present invention, a cavity is formed between the seamless tube 2 and the fiber 1 with the fiber grating, and a heat conducting agent may be disposed in the cavity. When the fiber grating sensor measures the temperature, the heat conducting agent conducts heat, so that the temperature measured by the fiber grating sensor and the ambient temperature tend to be consistent faster.

In some embodiments, a gap is provided between the sealed end 4 and one end of the optical fiber 1 with the fiber grating, which is close to the sealed end 4, different substances can be filled according to different requirements, and matching fluid or matching paste can be filled for changing reflection and refraction indexes of the optical fiber 1 with the fiber grating so as to avoid affecting connected fiber grating sensing equipment, thereby improving the measurement result. When the end cap is adopted for packaging, the filler can be placed in the end cap in advance.

The seamless pipe 2 may be made of stainless steel, or other corrosion-resistant alloy pipes, or different types of metal pipes such as an aluminum pipe and a copper pipe, depending on the use environment.

In some embodiments, the fiber grating sensor sleeved with one layer of seamless metal tube 2 can be nested into another layer of seamless metal tube, or nested into a plurality of layers of seamless metal tubes, and the outermost layer of seamless metal tube is wrapped with an insulating tube 5 to form the fiber grating sensor nested with the plurality of layers of tubes.

In some embodiments, the fiber grating sensor sleeved with one layer of seamless tube 2 can be nested into another layer of wrapped metal tube, or after steel wires are nested and stranded, an insulating tube 5 is wrapped on the outer layer of the fiber grating sensor to form the fiber grating sensor with higher strength.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A fiber grating sensor comprises a fiber joint (3), a fiber (1) with a fiber grating, which is extended from the fiber joint; the other end of the optical fiber is a closed end (4) or extends into another optical fiber joint; the seamless tube (2) is sleeved on the outer side of the optical fiber (1), and the optical fiber is characterized in that the outer side of the seamless tube is further coated with an insulating tube (5).

2. The fiber grating sensor according to claim 1, wherein the fiber grating on the optical fiber (1) is a single-point fiber grating or a multi-point fiber grating.

3. The fiber grating sensor according to claim 1, wherein the seamless tube (2) is a seamless metal tube or a seamless alloy tube.

4. The fiber grating sensor according to claim 1, wherein the seamless tube (2) is a seamless steel tube or a seamless aluminum tube or a seamless copper tube.

5. The fiber grating sensor according to claim 1, wherein the insulating tube (5) is a rubber tube.

6. The fiber grating sensor according to claim 1, wherein the insulating tube (5) is a plastic tube.

7. The fiber grating sensor according to claim 1, wherein the insulating tube (5) is a resin tube.

8. The fiber grating sensor according to claim 1, wherein the closed end (4) is sealed by welding, end cap or glue.

9. The fiber grating sensor according to claim 1, wherein a wrapped metal tube or a stranded steel wire layer is further nested between the seamless tube (2) and the insulating tube (5).

10. The fiber grating sensor according to claim 1, wherein the insulating tube (5) coated with the seamless tube has an outer diameter of 0.2 to 3.2 mm.